A prior art fitted bed sheet has a total four pockets, with two pockets in the front and two pockets in the back. Each pocket receives a corner of a mattress. To put the prior art fitted bed sheet on the mattress, the corners of the mattress are lifted up and inserted into the pockets.
However, lifting up the corners, such as the back corners, of the mattress is often difficult because the back corners are usually not easily accessible, especially in a bunk-bed setting. Further, some mattresses, such as memory foam mattresses, are heavy. Fitting a corner of a mattress into a pocket of the prior art fitted bed sheet while lifting up the corner of the mattress is difficult and can easily cause frustration.